Fluid operated control apparatus responsive to sensing a plurality of members containing one of two codes

ABSTRACT

Fluid operated apparatus for controlling the operation of a device actuator that is connectable in an electric circuit and adapted to be energized in response to sensing of the presence of a particular coding on a film cartridge or other member. Fluid operated means senses the coding on a cartridge and selectively controls the application of fluid pressure to a fluid operated switch so that the switch is opened or closed according to the coding sensed. Electrical contacts of the switch are connectable in a circuit including the device to be controlled so that the device is operated only in response to the presence of a cartridge having a particular code thereon. In a preferred embodiment disclosed the apparatus is adapted to sense two particular cartridge codes and to operate a punch used to strip film from the cartridge only when a conditioning switch on a film processor indicates that the processor is set to handle the film type that is in the cartridge.

United States Patent Sukel t [541 FLUID OPERATED comnoL APPARATUS RESPONSIVE TO SENSING A PLURALITY OF MEMBERS CONTAINING ONE OF TWO CODES [72] lnventor: Gerald Sulrel, Rochester, N.Y.

[73] Assignee: Eastman Kodak Company,

Rochester, N.Y.

[22] Filed: Nov. 9, 1970 [21] App1.No.: 88,033

[52] US. Cl ..307/144, 137/81.5, 200/D1G. 5,

ZOO/81.4, 200/81 R [51] Int. Cl... ..lllllh35/24,F15c1/08 [58] Field of Search .'...200/42, 44, 46, 81 R, 81.4, ZOO/81.5, DIG. 5, 8311; 137/815, 552.5; 307/118,144; 192/131 [56] References Cited UNITED STATES PATENTS 3,534,329 10/1970 Greene ..200/8l.4 X 3,051,872 8/1962 Cowherd ..307/ 144 X 3,509,898 5/1970 Monge et a1 ..l37/81.5 3,542,049 1 1/1970 Kobayashi et a1. ..137/81.5 3,427,417 2/1969 Hope ..200/83 R 2,944,558 7/1960 Dodge ..200/81 R X I 3,317,039 v 3,270,960. 9/1966 Phillips. ..235/201 dress s] 3,702,40 [451 Nov. 7 1972 5/1967 Wadey. ....l37/81.5 X

' Primary Examiner-Robert K. Schaefer Assistant Examiner-Robert A. Vanderhye' Attorney-Robert W. Hamptonand G. Herman Chil- [57 ABSTRACT Fluid operated apparatus for controlling the operation of a device actuator that is connectable in an electric circuit and adapted to be energized in response to sensing of the presence of a particular coding on a film cartridge or other member. Fluid operated means senses the coding on a cartridge and selectively con- ,trols the application of fluid pressure to a fluid.

operated switch so that the switch is opened or closed according to the coding sensed. Electrical contacts of the switch are connectable in a circuit including the ,device to be controlled so that the device is operated only in responseto the presence of a cartridge having a particular code thereon. ln a preferred embodiment disclosed the apparatus is adapted to sense two particular cartridge codes and to operate a punch used to strip film from the cartridge only when a conditioning switch on a film processor indicates that the processor is set to handle the film type that is in the cartridge.

5 Claims, 4 Drawing Figures Reference is made to commonlyassigned co-pending I U.S. Pat. application Ser. No. 61,594, entitled FILM' PROCESSING APPARATUS FOR PROCESSING FILMS OF DIFFERENT TYPE, filed in the name of E. \lV, Jensen on Aug. 6, 1970. I.

BACKGROUND OF THE INVENTION The beforementioned copending application discloses a film processor thatis adapted to handle two different types of films. A switch in the processor is set to either of two operative-positions so that when a cartridge containing film is presented, suitable cartridge sensing means cooperate with that switch to permit operation of adevice for extracting film from the cartridge only if the switch is set at a position that-condi-- tions the apparatus for handling the type of film sensed by the cartridge sensing means; The present application tion' is to provide such apparatus which is fluid operated and whereinonly slight pressure need be exerted for sensing.

In accordance withthe present invention, apparatus is provided for controlling the operation of a device in member. The apparatus includes fluid operated electrirelatesto a particular apparatus for sensing a particular code or codes on cartridges, andfor cooperating with the switch disclosed in the copending application for actuating the device, such as a punch or the like.

Various fluid controlled or fluid operated devices are well known for sensing the presence (or absence) of a work piece and for controlling operation of a devicein response to such sensing. For example, sorting apparatus used for sortingfperforated cards used in data processing machines are frequently fluid operated.

However, prior film processing film apparatus have relied primarily on an operator visuallydetermining the Also, such manual detection of aparticular film type is 4 filmtypes andsubstan'tially I00 percentaccuracy in detection of the type of film being fed to the apparatus. Mechanical and photoelectric sensing devices are not altogether suitable for sensing film cartridges due to lack of reliability over long periods of operation and/or danger of exposing film to alight beam.

SUMMARY OF THE INVENTION Accordingly'it is an object of the invention to provide fluidic apparatus for controlling the operation of a device, such as a portion of a film processor, in response to the sensing of the presence of a member having thereon means defining a code identifying the member so that the device is operated only when the proper-code is sensed by the apparatus; and to provide such apparatus that is capable of sensing more than one code and for cooperating'with a multi-p'os'ition switch paratus of the invention a device;

cal switch means having a fluid inlet and having means communicating withthe inlet for changing the switch means from one stateto another state in response to fluid pressure conditions atthe inlet. The switch means means on said member and for varying the fluid presin response tosuch sure condition at the fluid inlet sensing.

BRIEF DESCRIPTION OF THE DRAWINGS I In the detailed description of the preferred embodiments of the invention presented below, reference is madeto the accompanying drawings, in which:

FIG. 1 is a schematic view of fluid operated apfor controlling the operation of FIG'. 2 is an enlarged detail view showing a portion of the apparatus for sensing coding on a camera cartridge or the like;

FIG. 3 is a view similar to FIG. 2 showing a cartridge or other member being sensed by the apparatus; and

FIG. 4 is a fragmentary view of a camera cartridge having coding thereon, defined by notches that can be sensed by using the apparatus of the invention.

I DESCRIPTION OF THEPREFERRED EMBODIMENT Because photographic apparatus are well known, the present description will be directed inparticular to: elements forming part of, or cooperating more directly with, ,the present invention, photographic apparatus not specifically shown or described herein being understood to be selectable from those known in the art.

By way of example, the preferred embodiment of the apparatus of the invention is disclosed in connection with film processing apparatus of the general type disclosed in the commonly assigned, copending U.S. Pat. application entitled FILM PROCESSING METHOD AND APPARATUS, Ser. No. 820,379, filed on Apr. 29, 1969 in the name of James L. Hart et al., now abandoned in favor of continuation application No. 126,979. Also, apparatus for processing films of various types is disclosed in the commonly assigned, copending US. Pat. application Ser. No. 61,594, entitled FILM PROCESSING; APPARATUS FOR PROCESSING FILMS OF DIFFERENT TYPE, filed on Aug. 6, 1970 in the name of'Einar W. Jensen. The latter application discloses a film processor apparatus having two chambers for processing liquids, one of which is used for processing a film of one type or ASA number, and the other of which is used for processing film of a-different type or ASA number. For example,

v the processor may handlelfilms having film speed ratings ofeither ASA" 40 or ASA by selectively passing film through one or the other of the chambers. As the processor is being set up, a conditioning switch, such as shown at in the present application, is set to either one of two closed positions wherein a movable switch member 12 is brought into engagement with a switch contact 14, or alternatively, a switch contact 16. Switch member 12 is connected to a source of electrical potential, such as by an electrical connector 18. Also connected to the source of electrical'potential or connector 18 is an electrically energizable device shown schematically at 20. The device 20 may be, for example, an electrically operable punch device such as disclosed'in the'commonly assigned copending U.S. Pat. application Ser. No. 813,526, filed Apr. 4, 1 969 in the names of Robert C. Sutliff and Archie J. Tucker,

entitled CARTRIDGE AND METHOD FOR REMOV lNG FILM FROM THE CARTRIDGE, now US. Pat. No. 3,5 50,877. The punch device described in that application is operable to penetrate the side walls of a-filrn cartridge such as shown in FIG. 4 for disabling an antibackup mechanism (not shown) within the cartridge, thereby to permit extraction of film from the. cartridge through an exposure aperture in the cartridge; The apparatus of the present invention is adapted to sense the coding on a'cartridge that is indicative of characteristic offilm in a cartridge presented to such film processing film cartridge generally designated 22. The cartridge has an end wall 24 withan aperture 26 therein through whichfilm F in the cartridge can be exposed and through which film can be extracted from the cartridge in the manner described in the. beforementioned copending applicationin the name of Sutliff et al. Wall 24 of the'cartridge normally is provided. with code markings in the form of notches 28, and 32. Notch 28 conventionally designates the ASA film speed or rating of the film contained within the cartridge. Notch 30 normally is used as a product identification notch, and it is this notch that is sensed by apparatus of this invention. The presence of a notch as shown at 32 indicates that the cartridge is loaded with film that requires exposure by artificial light. In addition, the cartridge can be provided with a centrally-located slot 34 that is used for positioning the cartridge accurately in a camera or in film processing apparatus.

Referring now to FIGS. l-3, the apparatus of the present invention comprises a manifold 40 having a fluid inlet 42 through which air or other gaseous fluid under pressure is adapted to be furnished to the manifold from a supply line diagrammatically shown at 44. The manifold has a plurality of outlet ports or openings 45 that preferably are equally spaced along the length of the manifold. Four such ports or outlets are illustrated in the drawings; however, more or fewer ports can be provided, depending upon, the variety. of codes to be sensed by the apparatus. Each of the outlet v 56 to a fluidic-to-electric switch generally designated conduit normally is open to'permit venting of fluid from the manifold throughthe various passages. However, if the open end of aconduit is closed (by a solid portion of cartridge 22 adjacent notch 30, for example), then there is a slight increase in the fluid'pressure in the other (right) end of the conduit or passage. Thus the fluid pressure conditions in conduits 46-52 can be used to determine the presence of a cartridge having a particular arrangement of code notching indicative'of a film .type or characteristic. In order to simplify the drawings, the cartridge is shown positionedv directly against one end of conduits 46-52. However, in prac tice, these conduits may be connected to a cartridge holder (not shown) that locates end wall 24 of the cartridge properly for fluid sensing by the apparatus of the invention and for stripping of film from the cartridge.

} Each conduit 48 and 50 has at its right end two branch passages 48b, 48c and 50b and 500. The right end of passages 46, 48b and 50b are connected to a fluidic device 56, and the right end of fluid passages 50c, 48c and 52 are connected to a similar fluidic device 58. The fluidic devices 56 and 58 are preferably conventional fluidic industrial control modules known as OR/NOR gates that are available from various industrial sources, including the-Fluidic Products Department, Corning Glass Works, Corning, New York. Device 56 has a fluid inlet connected via conduit 60 to the source 44 of fluid under pressure. The device 56 has two fluid outlets connected to a fluid vent 62 and to aconduit or fluid passage 64. Normally, air or other fluid under pressure entering the device 56 through supply conduit 60 is exhausted through vent 62. However, in response to an increasein fluid pressure in any or all of the inlet conduits 46, 48 and/or 50, fluid furnished to the device through conduit 60 is directed into the passage or fluid conduit64, thereby increasing the fluid pressure in that conduit. In a similar manner, device 58 normally receives fluid under pressure from source 44 through a fluid supply conduit 66 connected to the fluid inlet ofthe device. Normally air is vented from the device through a vent or outlet 68. When fluid pressure increases in any or all of conduits 48, 50 and/or 52, fluid under pressure entering the device from line 66 is provided to a conduit or fluid passage 70 thereby increasing the fluid pressure in that passage. In the embodiment disclosed the apparatus is intended to sense cartridge coding that either blocks conduit end 46a and leaves unblocked conduit ends 48a, 50a and 52a or blocks end 52a and leaves ends 46a, 48a and 50a unblocked. For this particular code sensing'conduits 46 and 52 may be considered control conduits.

since device 56 is responsive to changes in fluid pressure in conduit 46 and device 58 is responsive to changes in fluid pressure in conduit 52. Of course, this particular coding is merely representative of various notching combinations that can be sensed by the apparatus so that any or all of conduits 46, 48, 50 and 52 may be controlconduits. Thus the provision of conduits 48 or 50 permit sensing of additional film types.

Passage 64 couples the output of the OR/NOR gate entering the device 74 through 'passage76 is vented through a first outlet to a passage or conduit 78. However, when there is an increase in fluid pressure in passage 64 due to an increase inthe fluid pressure in the control passage 46, then fluid entering device 74 through conduit 76 is discharged from the device into a passage or conduit 80. v i 1 Passages 78 and 80 are connected to a double pole, double throw, diaphragm-operated electric switch generally designated 82 andcornprising a firstpair of electrical contacts 84d and-84band a second pairof electrical contacts 86a and 86b. A switch contact member 88, which isunormally spring biased against electrical contacts-84a and 84b to completea circuit therebetween, can be moved to the left (as viewed in FIG. 1) into engagement .with contacts 861: and 86b, thereby to establish electrical contact between such contacts and to terminate the electrical contact betweenthe contact members 84a and 84b.'Thismovement of the switch member against itsspring bias to change the switch from one state to another is achieved in response to an increase in fluid pressure in passage 80. When fluid under pressure is directed from device 74 into passage 78, the resulting increase in fluid pressure at the left side of the diaphragm or switch member (and the corresponding decrease in pressure in line 80) helps the switch spring move the contact member to the position shown in FIG. 1 and maintain'the switch closed to contacts 84a, 84b.

A second fluidic-to-electric switch is generally designated 90 and it is similar in constructionand under pressure furnished to devices 56 and 58 from.

operation to switch 72. Switch 90 comprises afluidic device 92 that normally receives at its inletfluid under pressure through conduit or passage 94 and the fluid pressure source 44. Normally, this fluid is discharged to a conduit orpassage 96. Device 92'also is connected to passage 70 so that an increase in fluid .pressure inv passage-70 deflects fluid entering the device through passage 94 and provides such fluid into a control conduit or passage 98. Switch 90 furtherincludes a first pair of electrical contacts 100a, 100b and a second pair construction to the switch 72 except that the contacts 100a and 102a are electrically interconnected by a conductor 106.

1 Contact 84a of switch 72 is connectedby a'conductor 108 to terminal or contact 14 of switch 10, and the other terminal or contact 16 of switch 10 is connected by conductor 1 10 to contact 86a. Contact 84b of switch 72 is connected by-a conductor 112 to contact 102b of switch 90, and. switch contacts 861) and 100b are interconnected'by a conductor 114. Switch contacts 100a and 102a are connected to the device 20 by conductor 116.

'Operationof the apparatus of the invention will now be described. Firstof all, when none of the passage ends 46a, 48a, 50a or 52a are blocked, as will occur if no cartridge is presented to the apparatus or if the cartridge presented'has a sufficiently wide notch 30 to leave unblocked all of the passage ends, then fluid supply line 44 will be vented through their outlets 62 and 68, respectively. Therefore, no fluid under pressure is provided to passages 64 and and fluidoperatedswitches 72 and remain in the states shown in solid lines in FIG. 1. As a result, the electrical circuit to device 20 is open whether conditioning switch 10 is closedto contact member- 14 mm contact member 16.

Next it will be assumed thatthe contact member 12 is closed to switch contact 14' and thatthis conditions the film processingapparatus to receive film from a film cartridge 22 having coding that blocks the end 52.. of passage 52 but leaves unblocked the ends 46a, 48a and 50aas shown in FIG. 1. The presence of such coding causes the fluid device 58 to provide fluid under pressure from conduit 66 of the device 58 to device 92 through the outlet conduit 70. This, in turn, provides fluid under pressure from device 92 to conduit 98 of the fluid to electric switch 90, thereby causing contact member 104 to move from engagement withcontacts 100a, 100b to engagement with the contacts 102a and tact member 88 and conductor 112 to switch contact 102b, a'cross switch member 104 to contact 102a, and then through conductor 106 and 116 to the device 20. Processing of film can proceed in the usual and normal manner. In a similar manner the actuator 20 will be energized if the switch contact member 12 is moved into engagement with the contact 16 and if a cartridge 22 presented to the apparatus has a notch 30 that closes the end 46a of passage 46 and leaves passage ends 48a, 50a-and 52a unblocked.

' Actuator 20 will not be energized unless the particular coding on a cartridge presented to the apparatus indicates the film in the cartridge is of the type that the processor can handle as determined by the position of switch 10. For example, if all of the passage ends 460, 48a, 50a and 52a are blocked by a cartridge having no notches, then both of the fluid-to-electric switches 72 and 80 are switched. As a result the electrical circuit to actuator 20 remains open. Thus it will be seen that the apparatus of the present invention verifies presorting of cartridges and permits operation of the actuator only when the cartridge presented is notched to indicate a film type or characteristic that corresponds to the setting of the conditioning switch 10 of the film processor. The apparatus of the invention is particularly desirable for sensing a code where photoelectric or mechanical systems are not desirable. Very little pressure is required to operate the fluidic devices 56 and 58, typically less than H 100th of one pound per square inch being sufficient for operation of these devices. While the apparatus of the invention has been described in connection with the sensing of a particular code on film cartridges, and in connection with the operation of film processing apparatus it will be apparent to those skilled in the art that codes on articles other than cartridges can be sensed, and that the apparatus can be used in connection with devices other than an actuator for a film processor.

The invention has been described in detail with particular reference to preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.

1. Apparatus for controlling the operation of an electrically energizable device in response to sensing the presence of film cartridges containing either one of two types of film to be processed by a film processor, the cartridges each having on one surface thereof means defining one of two identifiable codes indicative of a characteristic of film within the cartridge, the device being connectable in a circuit including a processor conditioning switch that can be set to either of two closed positions for conditioning the processor to handle film having two differentcharacteristics, the apparatus comprising: I

two fluid operated electrical switches, each of said switches having (1) two pairs of electrical contacts, (2) a fluid inlet for receiving fluid under pressure, (3) a movable member for completing a circuit between one or the other of said pairs of contacts in response to fluid pressure conditions at said inlet, and (4) means operably associated with said member for moving saidmember to selectively open and close the circuit between said pairs of contacts in response to fluid pressure conditions at said fluid inlet, said contacts being adapted to be connected in a circuit including said device and said conditioning switch;

two fluid operated OR/NOR gates, each of said gates having (1) a fluid inlet adapted to be connected to a source of fluid under pressure, (2) a first fluid outlet through which fluid from the inlet normally is discharged, (3) a second fluid outlet, and (4) a second inlet adapted to receive fluid under pressure and to effect dischargeof fluid from the gate through the second outlet, the second fluid outlet of a first one of said gates being connected to the inlet of one of said switches and the second fluid outlet of a second one of said gates being connected to the fluid inlet of the other of said switches;

means connected to the second inlet of each of said gates for providing fluid under pressure thereto to actuate the gate to provide fluid from the first inlet to the second outlet thereof in response to sensing of particular codes on cartridges; and means completing electrical circuits between said pairs of contacts of said switches, said conditioning switch and said device so that a particular cartridge coding can be sensed by said gates for operating one or the other of the fluid operated switches to complete a circuit to the device and the conditioning switch if the conditioning switch is set to a position indicating the processor is set to process film of the type contained in the cartridge as indicated by the coding on the cartridge.

2. Apparatus for controlling the operation of an electrically energizable device in response to sensing on a plurality of members to be furnished to the apparatus one of two distinctly different codes used for identifying the members, the apparatus comprising:

an electrical circuit comprising first and second fluidic-to-electric switches adapted to be connected for regulating operation of the device, each of said fluidic-to-electric switches having (1) means for receiving a fluid under pressure and (2) electrical switch means changeable from a first state to a second state in response to pressure conditions of a fluid furnished to the fluid receiving means, said switches being electrically connected in the circuit so that the device can be energized if one of the switch means is in its second state; means for controlling the states of said switch means comprising (1) means for sensing each of the two codes and (2) means coupling said sensing means to the fluid receiving means of said fluidic-to-electric switches for (a) effecting a change in the con-, dition of the fluid furnished to said first fluidic-toelectric switch tochange itsswitch means to its second state in response to sensing the presence of one of the codes and (b) effecting a change in the condition of the fluid furnished to said second fluidic-to-electric switch to change its switch means to its second state in response to sensing the presence of one of the codes; and a conditioning switch having two closed positions for conditioning the device to handle members having one or the other of the different codes identifying the members, said conditioning switch being connected in the circuit so that'(1) when it is set to one of its closed positions it permits energization of said device when the presence of a member having one of said codes is sensed by said sensing means and (2) when it is set to the other of its closed positions it permits energization of said device when the presence of a member having the other of said codes is sensed by said sensing means. .3. Apparatus as set forth in claim 2 wherein the means for controlling the state of said switch means comprises a fluid-operated device'having (1) an inlet for receiving fluid, (2) a first fluid outlet through which fluid normally is vented from the device, and (3) a second fluid outlet through which fluid can be discharged from the device in response to fluid pressure conditions at the inlet, the second fluid outlet being connected to said switch means.

4. Apparatus as set forth in claim 2 wherein said means for controlling the states of said switch means comprises two fluidic OR/NOR gates, each of said gates having (1) a fluid outlet connected .to said receiving means of one of said switch means and (2) a fluid inlet connected to said sensing means for receiving fluid from said sensing means, said gates being operable to provide fluid under pressure to said switches in response to the sensing of a member containing one of said codes.

5. Apparatus as set forth in claim 2 wherein said switch means of said switches are electrically con nected in said circuit so that the circuit is ineffective to operate the device when both of said switch means are in their first state or in their second state. 

1. Apparatus for controlling the operation of an electrically energizable device in response to sensing the presence of film cartridges containing either one of two types of film to be processed by a film processor, the cartridges each having on one surface thereof means defining one of two identifiable codes indicative of a characteristic of film within the cartridge, the device being connectable in a circuit including a processor conditioning switch that can be set to either of two closed positions for conditioning the processor to handle film having two different characteristics, the apparatus comprising: two fluid operated electrical switches, each of said switches having (1) two pairs of electrical contacts, (2) a fluid inlet for receiving fluid under pressure, (3) a movable member for completing a circuit between one or the other of said pairs of contacts in response to fluid pressure conditions at said inlet, and (4) means operably associated with said member for moving said member to selectively open and close the circuit between said pairs of contacts in response to fluid pressure conditioNs at said fluid inlet, said contacts being adapted to be connected in a circuit including said device and said conditioning switch; two fluid operated OR/NOR gates, each of said gates having (1) a fluid inlet adapted to be connected to a source of fluid under pressure, (2) a first fluid outlet through which fluid from the inlet normally is discharged, (3) a second fluid outlet, and (4) a second inlet adapted to receive fluid under pressure and to effect discharge of fluid from the gate through the second outlet, the second fluid outlet of a first one of said gates being connected to the inlet of one of said switches and the second fluid outlet of a second one of said gates being connected to the fluid inlet of the other of said switches; means connected to the second inlet of each of said gates for providing fluid under pressure thereto to actuate the gate to provide fluid from the first inlet to the second outlet thereof in response to sensing of particular codes on cartridges; and means completing electrical circuits between said pairs of contacts of said switches, said conditioning switch and said device so that a particular cartridge coding can be sensed by said gates for operating one or the other of the fluid operated switches to complete a circuit to the device and the conditioning switch if the conditioning switch is set to a position indicating the processor is set to process film of the type contained in the cartridge as indicated by the coding on the cartridge.
 2. Apparatus for controlling the operation of an electrically energizable device in response to sensing on a plurality of members to be furnished to the apparatus one of two distinctly different codes used for identifying the members, the apparatus comprising: an electrical circuit comprising first and second fluidic-to-electric switches adapted to be connected for regulating operation of the device, each of said fluidic-to-electric switches having (1) means for receiving a fluid under pressure and (2) electrical switch means changeable from a first state to a second state in response to pressure conditions of a fluid furnished to the fluid receiving means, said switches being electrically connected in the circuit so that the device can be energized if one of the switch means is in its second state; means for controlling the states of said switch means comprising (1) means for sensing each of the two codes and (2) means coupling said sensing means to the fluid receiving means of said fluidic-to-electric switches for (a) effecting a change in the condition of the fluid furnished to said first fluidic-to-electric switch to change its switch means to its second state in response to sensing the presence of one of the codes and (b) effecting a change in the condition of the fluid furnished to said second fluidic-to-electric switch to change its switch means to its second state in response to sensing the presence of one of the codes; and a conditioning switch having two closed positions for conditioning the device to handle members having one or the other of the different codes identifying the members, said conditioning switch being connected in the circuit so that (1) when it is set to one of its closed positions it permits energization of said device when the presence of a member having one of said codes is sensed by said sensing means and (2) when it is set to the other of its closed positions it permits energization of said device when the presence of a member having the other of said codes is sensed by said sensing means.
 3. Apparatus as set forth in claim 2 wherein the means for controlling the state of said switch means comprises a fluid-operated device having (1) an inlet for receiving fluid, (2) a first fluid outlet through which fluid normally is vented from the device, and (3) a second fluid outlet through which fluid can be discharged from the device in response to fluid pressure conditions at the inlet, the second fluid outlet being connected to said switch means.
 4. Apparatus as set forth in claim 2 wherein said means for controlling the states of said switch means comprises two fluidic OR/NOR gates, each of said gates having (1) a fluid outlet connected to said receiving means of one of said switch means and (2) a fluid inlet connected to said sensing means for receiving fluid from said sensing means, said gates being operable to provide fluid under pressure to said switches in response to the sensing of a member containing one of said codes.
 5. Apparatus as set forth in claim 2 wherein said switch means of said switches are electrically connected in said circuit so that the circuit is ineffective to operate the device when both of said switch means are in their first state or in their second state. 